Making a long overdue debut at Ronnie Scott’s — “I guess that’s so, apart from a couple of jam sessions” — is this fine US tenorist, who first impressed London a decade ago in a group led by Clint Eastwood’s bassist son, Kyle. A commanding improviser with a hard-edged yet warm sound, his probing harmonic approach reflects George Coleman more than the usual Rollins and Coltrane.

Tall and upright, he’s also one of the superfit new breed of jazz professionals, a product of jazz conservatories rather than smoky basements. He runs half-marathons and likes jogging around a new city before playing its nightclubs. Fans who braved a freezing Bank Holiday Monday to catch his opening night were rewarded with a well-paced set of flab-free contemporary jazz.

Though new to one another, Danish drummer Kristian Leth, Hungarian bassist Arnie Somogyi and British pianist James Pearson made an excellent rhythm section and tenorist Dave O’Higgins responded brilliantly to the challenge of playing alongside Alexander. At times their booting ensembles recalled the past glories of two-tenor groups such as Sonny Stitt and Gene Ammons or Johnny Griffin and Eddie “Lockjaw” Davis. When they resume rivalries again tonight, they will probably sound even better.

Until tomorrow (020 7439 0747)